Fontem paginae Joulium inspicere

{{Movenda|Iulium|tempus=20240424154012|disputatio=petitio-temporis-20240424154012-vicipaediani}}

'''Iulium'''{{MLAL ref|.phys joule|395}}{{DAEL ref|julio|609}}{{LLHL24 ref|Joule|55}} (symbolum: '''J''') est [[unitas]] in [[SI|Systemate Internationali]] (SI), quae [[energia]]m, [[calor]]em, [[electricitas|electricitatem]], et [[labor (physica)|laborem mechanicum]] describit, et scilicet ex [[Iacobus Prescott Joule|Iacobo Prescotto Iulio]] appellatur.

1J valet ac labor quo 1[[newtonium|N]] moveatur 1[[metrum|m]], vel [[lingua]] [[mathematica]]:
:<math>\, 1\, \mathrm{J}=1\, \mathrm{N} \cdot \mathrm{m}</math>
<br />
:<math>\, 1\, \mathrm{J}=1\, \mathrm{kg} \cdot \frac{\mathrm{m}^{2}}{\mathrm{s}^{2}}</math>

<!--One joule is also:
* The work required to move an [[electric charge]] of one [[coulomb]] through an electrical potential difference of one [[volt]]; or one coulomb volt, with the symbol C·V.
* The work done to produce power of one [[watt]] continuously for one [[second]]; or one watt second (compare [[kilowatt hour]]), with the symbol W·s. Thus a kilowatt hour is 3,600,000 joules or 3.6 megajoules

== History ==
A joule is the mechanical equivalent of heat meaning the number of units of work in which the unit of heat can perform. Its value was found by [[James Prescott Joule]] in experiments that showed the mechanical energy Joule's equivalent, and represented by the symbol J. The term was first introduced by Dr. Mayer of Heilbronn.

== Conversions ==
{{main|Conversion of units#Energy, work, or heat}}
1 joule is exactly 10<sup>7</sup> [[erg]]s.

1 joule is approximately equal to:
* 6.24150636309 {{e|18}} eV ([[electronvolt]]s) 
* 0.238845896628 cal ([[calorie]]) (small calories, lower case c)
* 2.390 {{e|−4}} kilocalorie, Calories (food energy, upper case C)
* 9.47817120313 {{e|−4}} BTU ([[British thermal unit]])
* 0.737562149277 ft·lb<sub>f</sub> ([[foot-pound force]])
* 23.7 ft·pdl (foot [[poundal]]s)
* 2.7778 {{e|−7}} [[kilowatt hour]]
* 2.7778 {{e|−4}} watt hour
* 9.8692 {{e|−3}} litre-[[atmosphere (unit)|atmosphere]]

Units defined in terms of the joule include:
* 1 thermochemical [[calorie]] = 4.184 J
* 1 International Table calorie = 4.1868 J
* 1 watt hour = 3600 J
* 1 kilowatt hour = 3.6 {{e|6}} J (or 3.6 MJ)
* 1 ton TNT = 4.184 GJ

Useful to remember:
* 1 joule = 1 newton metre = 1 watt second

1 joule in everyday life is approximately:
* the energy required to lift a small apple one [[meter]] straight up.
* the energy released when that same apple falls one meter to the ground.
* the amount of energy, as [[heat]], that a quiet person generates every hundredth of a second.
* the energy required to heat one gram of dry, cool [[Earth's atmosphere|air]] by 1 degree Celsius.
* one hundredth of the energy a person can get by drinking a single drop of [[beer]].
* the kinetic energy of an adult human moving 17 cm every second.

=== SI multiples ===
{{SI multiples
|unit=joule
|symbol=J
|note=Common multiples are in bold face
|m=|k=|mc=|M=|n=|G=|p=|T=
}}

{{SI unit lowercase|James Prescott Joule|joule|J}} -->

{{NexInt}}
* [[Conversio unitatum]]
* [[Entropia]]
* [[Ordines magnitudinis]]
* [[Ordines magnitudinis (energia)]]
* [[Praefixa SI]]
* [[Thermodynamica]]<!--
* [[Electronvolt]]
* [[Kilowatt hour]]
* [[Fluence]]
* [[Foe (unit of energy)|Foe]]-->

== Notae ==
<references/>
<!-- * [http://www.fao.org/docrep/meeting/009/ae906e/ae906e17.htm The adoption of joules as units of energy], FAO/WHO Ad Hoc Committee of Experts on Energy and Protein, 1971. A report on the changeover from [[calorie]]s to joules in nutrition.-->

== Nexus externi ==
* [https://web.archive.org/web/20201219030333/http://formularium.org/?go=122 Convertere unitates a iuliis]

{{stipula}}
{{Unitates SI}}
[[Categoria:Unitates physicae]]

{{Myrias|Physica}}